It is necessary for successful horticulture in a greenhouse to provide light sources at specific luminosities and colors/spectrums to plants grown inside the greenhouse so as to facilitate the photosynthesis of the plants. Typically artificial light sources, i.e., plant supplemental lamps, is provided as the light sources for the plants grown inside the greenhouse, and at present a major challenge is how the plant supplemental lamps provide light energy required for the plants to grow.
At present plant LED lamps is typically provided as the artificial light sources for horticulture in the greenhouse, where the plants in a growing area of the greenhouse are grown at a sequence of locations under the plant LED lamps so that lighting is provided by the plant LED lamps to all the pants in the growing area.
However the existing plant LED lamps have a low profile and are compact, and their LED chips are concentrated in a small footprint resulting in small areas of the light sources; and the Plant LED lamps are hung over the plants, and the area of the growing area is much larger than the areas of the light sources of the plant LED lamps. As per the inverse square law of light radiation, the longer the distance from a light source is, the lower the amount of radiated light energy will be. If the distance of a plant from a light source is doubled, then the amount of light energy with which the plants are radiated will be lowered by a factor of ¼. As can be apparent from the simple calculation, it is impossible to provide all the plants with light at the same radiated energy from the compact plant LED lamps hung over the growing area of a large area, where only the plants in a fraction of the area immediately below the plant LED lamps are radiated with sufficient light energy, but the plants outside the area immediately below the plant LED lamps are radiated with light energy down to 25%, thus resulting in non-uniform growing of the plants in the same growing area.